Process for applying firmly-adhesive metal casings to iron cores.



P. E. PRESCHUN. NG FIRMKLY ADHESIVE METAL CASINGS APPLlcAnoN man we so.m16.

T0 XEON CORESv Patented Oct. 9,4917.

PROCESS FDH APPLY! Say UNITED STATES PATENT OFFICE.

i PAUL ERNST PRESCHLIN, 0F OBERUZWIL, SWITZERLAND.

PROCESS FOR APPLYING FIRMLY-ADHESIVE METAL CASIN'GgS T0 IRON GORES.

Application led August 80, 1916.

To all whom z't may concern:

Bc it known that I, PAUL ERNST Prinsen- Lin, wngincer, a citizen ofSwitzerland, rcuidingj at Oberuzwil, Canton St. Gallon. and :Sililadern-on-the-Sieg, Switzerland, have ingented certain new and usefullmprove- .meres in Processfs for Applying Firmly- Adhesive Metal /asingsto Iron Cores, of which the following is a specification, referencebeing had therein to the accompanyin drawing.

The invention relates to -imprm'ements in processes for the Securing oimetal casings on metal cores in the presence oi' heat.

In thc now known processes of this char actor, it has heen the practiceto expand and contract a casing, under the influent-c of heat, onto acore for the securing of the same together, but, due to the fact thalthedegree of contraction iS not always equal to that of the expansion, thedesired intimate Contact or binding pressure does not obtain fortheproper securing of the parts.

The primary object of the present invention is, therefore, to overcomethis very objectionable feature heretofore obtaining in such processes,and to accomplish this result, it contemplates the providing of a meansfor preventing any and all possible expansion of the casing, this meanshaving a cocfiicient of expansion less than that of the casing, so as toexert a counter-pressure in opposition to that pressure produced by thecasing and core, and which conselpicuU canses-the contacting surfaces ofthe p to firmly adhere one with the other when. allowed to cool afterheating.

The invention resides in the certain new and useful process as will behereinafter more fully described, set forth in the appended claims, andillustrated in the accompanying drawing, in winch:

Figure 1. `is a cross-section and fragmentary View of the preferredarrangement of the parts, when properly assembled for the4 carrying outof the process.

Fi 2 is a View, similar to Fig. 1, of a modi ed arrangement, and,

Fig. 3 is another View, also similar tol Fig. 1, showing a second modiedarrangement thereof. l r

In the accompanying drawing, in which similar characters of 'referencedesignada correspondin arts in the several views thereof, and 1n `g. 1thereof, the preferred Specification of Letters Patent.

Patented Oct. 9, 191'?.

Serial No. 117,759.

arrangluucut 'for the carrying out of the invention is shown, and thesaine comprises a core n, preferably cylindrical in Aform and made ofiron or steel, which is adapted to be inserted into a cylindrical easingc with u iilni of a suitable soldering metal b interposed between' theiropposed or contacting surfaces. In this instance, the `casing isentirely inclosod within a coil oi' iron wire d. preferably square orrectangular in crossscotion, the oonrolutious of which are disposed inclose contacting relation, as shown, and the coil is securely retainedin this VForni by means of' its` opposite ends being engaged in notches17 formed in the ends of the core u..

Referring to Fig. Z, a. modilied forni of the invention is shown, inwhich the core a, the film of solder Z), and tlie easing c areassemhled, as in Fig. 1, but the coil resistance e, performing similarfunction oi' that of the coil oi, is Wound over the surface oi' anauxillary iron casing 11 so that a concentric resistance is providedwherein its pressure is distributed equally over the entire surface ofthe parts to be secured together. This auxiliary casing i1, may beslotted, us at f, or in any other suitahlsl manner to facilitate itsassembly or removal to aud from operative position.

In Fig. 3, there is shown another form of the arrangement of parts forthe purpose of securing a casing on a core a of varying diameter, thesame being assembled Within a casing c, with a film of the solder binferposed therebetween. The easing c is shaped to conform to that ofthe core a, or otherwise as may be desired, and is inelosed within aninner resistance casing a7, which,`in turn, is inclosed lWithin an outerresistance Casin lo. The outer resistance casing Ic is preferaly of aform having a closed en l and an open e d, the latter bem provide with aremova le closure l, whic 1s secured to the casing by means of bolts orscrews m. yThe inner wall of the closed end of the casing k and theinner wall of the closure Z are preferably shaped to exert a clampingaction on the several parte assembled t erem, substantially as shown. i

In carryi g out the process in any instance, the m tal core is coatedwith any suitahlc` ux and: soldering material and is insertcdntoits\.casing, after the contacting surfaces of both ave been thoroughlycleaned and cleared fro impurities and oxids, the

casing being drawn through a suitable ga plate so that it is rmlypressed upon t e core, and all air, contained between the core and casinis ex elled. The resistance coil or casing 1s now orced over the metalcasing, and the whole is then ready for the application of heat thereto,for which pur ose the assembled body is placed into a suita le furnaceand heated u to a weldin tempera ture. When heate to the desirstempera.- ture, it is taken from the furnace, and stllowed to cool,after which the resistance coil or casing is then removed to completethe operation.

A This process may be carried out without the a lisation of the film ofsolder inten pose etween the core and its casing, in which case, thecontactin surfaces, after the heating operation, will e perfectly Weldedtogether, also the heatin of-the assembled body may be effected v anysuitable form of electric heating apparatus in lieu cf the ordinaryfurnace.

lt is to be fully understood that, while the invention has beenspecically described for use in connection with cylindrical bodies,cores and castings, various other forms of the letter may be made use ofwithout departing lfrom the spirit and scope of the invention.

What I claim as my invention and desire to secure by United StatesLettere Patent ve:--

1. The process of securing instal casings on metal cores, which consistsin assembling the core within the casing, heating the same to arelatively high temperature, `and sub jecting the casing to pressure toprevent its ex ension during the heating operation.

. The process of securin metal casings on metal cores, which consi s inassemblingv the core within the casing, heet the same toe weldingtempereture,'end seb eeting the casing to the action of a `resistancefor preventing its expansion during the heating operation.

3. The process of securin metal casings on metal cores, which consistsin cleaning the contacting surfaces of the core and casing forfreeingthe same from all impurities and oxide, assembling the corewithin the casing, heating the same to a welding ternpereture, andsubjecting the casing to the action of a resistance for preventing itsexpension during the heating operation.

4. The process of securmg metal casings on metal cores, which consistsin cleaning the contacting surfaces of the core and casing for freeingthe same from all impurities and oxids, assembling the core within thecasing, heating the same to a welding temperature, subjectin the easingto the action of a resistance or preventing its expansion during theheating operation, and then removing the resistance after the heut hasbeen completely dissipated.

5. The process of securing metal casings on metal cores, which consistsin cleaning the contacting surfaces of the core and casing for freeingthe same from all impurities and oxide, assembling the core within thecasing, nterposing a film of soldering material between the apposedwalls of the core and the casing, heating the same to a weldingtemperature, subjecting the casing to the action of a resistance forpreventing its expansion during the heating operation, and then removingthe resistance after the heat has been completely dissipated.

In testimony whereof I aiiix my signature in the presence of twowitnesses.

PAUL ERNST PRESCHLIN. Witnesses:

THOMAS LAUSEUR, EMIL' ScHNnmmz.

